The insulating qualities or properties of homes and other buildings can be significantly enhanced by the spraying within their outside and other walls of a foam resin produced by mixing a solution of a curable synthetic resin, for example, a urea-formaldehyde condensate, with a foamed solution of a foaming agent. A solution of a foaming agent provided with a curer or acid hardener for the synthetic resin, is first converted into a foam, and then is mixed as a foam with the solution of the sythentic resin.
The production of the insulating foam spray is attened by numerous problems. The synthetic resin has a short shelf life, and is constantly changing in viscosity due to aging and also to temperature changes. Heretofore, the foaming agent has had to be applied by forcing under pressure and in combination with compressed air through glass spheres or fine mesh screens having small holes subject to clogging by the resin residue as cured or hardened in the foam apparatus or gun by the acid hardener added to the foaming agent solution.
Further, the pressures at which the air, foaming agent and resin are delivered to and mixed or combined in the gun must be constantly monitored or adjusted, for best insulating quality or ideal density of the foamed resin, and to accommodate changes in the resin and temperature conditions.
Heretofore, it has not been possible with the available equipment to maintain the ideal density or wanted creamy consistency of the foam or to avoid excessive down time for cleaning of the equipment to rid it of the accumulating hardening resin residue, the spray delivery obstructing by which has produced a back pressure yielding in turn a clogging of the foam gun beads, blades, screens, orifices, stirrers and the like.
The insulating foam producing and delivering apparatus of this invention provides a foam gun from which the aforesaid beads, screens and the like, and hence the gun clogging thereby, are eliminated; to which means for monitoring and thereby correcting for clogging or backpressure buildup are added; and in which the combining of the foam with the resin is essentially confined to the applicator or dispenser hose.
While the invention apparatus or foam gun is thus minimally subject to the buildup of clogging residue, it is further provided with single-action means for conjoint shutoff of the metered air and pressurized foam and resin supplies, together with single action, bypass, full-air-pressure blowout of the gun.
The foam gun hereof is provided further, in combination with the virtually instant shutoff and blowout means, with a quick disconnect between the foam generating and foam-resin combining chambers, whereby upon shutoff, the gun may be separated for any needed cleaning of the parts while subjecting the equipment to the absolute minimum of downtime.
Further under this invention, the foam gun's air, foam and resin lines are provided with clear lengths, whereby the supplies to the foam generating and foam-resin combining chambers may be monitored or visually observed for unwanted changes or conditions, such as moisture in the air line signifying a water accumulation that must be removed from the air compressor.